As the MacBook power supply is a universal adapter (100 - 240 v AC, 50/60 Hz) you can use it anywhere in the world provided that you are able to connect to the local outlet configuration,
If your MacBook came with a 60W unit, you can use any power adapter that can supply 60 Watts or higher. This means that you can use a 60W or 85W unit with your MacBook. Remember that using a higher spec power adapter will not charge your 60 Watt MacBook any faster.